In electronic equipment having a display device such as a television or personal computer, glasses for switching between left-eye and right-eye images by liquid-crystal shutters are in common use as a 3D image display method.
A pair of “wireless 3D vision shutter glasses” disclosed in JP 64-19915 Y (Patent Literature 1) are an example of receiving a right-eye and left-eye liquid-crystal shutter switching timing signal by infrared communications. FIG. 12 shows an appearance perspective view, and FIG. 13 is a main-part enlarged sectional view of FIG. 12. A shutter switching timing signal sent by infrared rays, after received by a light receiving element 81, is converted to a liquid-crystal drive signal by a signal processing circuit 83, so that a right-eye liquid-crystal shutter 72 and a left-eye liquid-crystal shutter 73 are switched over. Reference sign 75 denotes a power supply unit, 86 denotes a glass frame, and 74 denotes a head band.
FIG. 14 shows a shutter control method in a “system, method and computer program product for controlling a three-dimensional glass shutter” disclosed in JP 2009-531979 A (Patent Literature 2). Shown at the beginning in FIG. 14 is an aspect that a first left-image L1 intended to be seen only by the left eye is transmitted via a communication medium 101. After this, a pause of transmission, i.e. a vertical blanking interval VB1, follows. Next, a first right-eye image R1 intended to be seen only by the right eye is transmitted, and the procedure is repeated similarly. Further, as it is shown, the right-eye shutter and left-eye shutter of the 3D glasses can be controlled independently of each other by using a plurality of signals (e.g., codes). This is achievable by utilizing, in this example, a right-eye control signal 104 for controlling the right-eye shutter and a left-eye control signal 105 for controlling the left-eye shutter. Still more, FIG. 15 shows another shutter control method. In this example, display contents transmitted to a display by an operation 111 can be received and buffered by such a fashion as shown by an operation 112. Display contents targeted for the individual eyes, after received and buffered by the operation 112, can be transmitted from the buffer to the display as further shown by the operation 112. For this purpose, the display is enabled to paint the individual display contents currently transmitted from the buffer (see an operation 113). It is noted that the display contents targeted for the individual eyes, after transmitted and painted, become holdable by the fashion shown in the figures.
A “sequential type 3D display unit” disclosed in JP 2010-78985 A (Patent Literature 3) is so designed that right-eye and left-eye images are presented alternately on time base and partial regions for writing right-eye and left-eye images, respectively, are illuminated alternately with a backlight. FIG. 16 depicts a state in which a right-eye image is presented to a viewer in this system. In this case, while a 1-frame image is displayed, right-eye image data is written into first regions (odd lines) of a display panel 121, and left-eye image data is written into second regions (even lines). Also, the first regions (odd lines) and the second regions (even lines) of a backlight 124 repeats light emission at a frequency of, for example, 1404 Hz or higher during a period of 1-frame image display. The viewer being fitted with shutter glasses 122, opening and closing of the shutter glasses is controlled in synchronization with the light emission repeating cycle of the backlight 124 so that the image reaches a corresponding eye, whether the image is for the right eye or the left eye.
As described above, glasses corresponding to individual display units are needed depending on differences in control method between the display unit and the shutter glasses.
According to the glasses disclosed in the above Patent Literatures 1-3, the glasses are indeed capable of realizing 3D images using binocular parallax in a wireless fashion, but those glasses are ones each corresponding to one display unit and incapable of driving the liquid-crystal shutters responsive to timing signals of other display units.
In addition, although some of other equipment such as infrared remote controls are provided with learning functions so as to be adapted to other methods, yet 3D video glasses necessitate some mechanism or technique that is not included in other equipment.